[Extensions Bindings] Add support for custom property types

extensions/renderer/api_binding.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef EXTENSIONS_RENDERER_API_BINDING_H_
 #define EXTENSIONS_RENDERER_API_BINDING_H_
 
 #include <map>
 #include <memory>
 #include <string>
@@ skipping 23 matching lines @@
 // A class that vends v8::Objects for extension APIs. These APIs have function
 // interceptors for all exposed methods, which call back into the APIBinding.
 // The APIBinding then matches the calling arguments against an expected method
 // signature, throwing an error if they don't match.
 // There should only need to be a single APIBinding object for each API, and
 // each can vend multiple v8::Objects for different contexts.
 // This object is designed to be one-per-isolate, but used across separate
 // contexts.
 class APIBinding {
  public:
+  using CreateCustomType =
+      base::Callback<v8::Local<v8::Object>(v8::Local<v8::Context> context,
+                                           const std::string& type_name,
+                                           const std::string& property_name)>;
+
   // The callback for determining if a given API method (specified by |name|)
   // is available.
   using AvailabilityCallback = base::Callback<bool(const std::string& name)>;
 
   // The callback type for handling an API call.
   using HandlerCallback = base::Callback<void(gin::Arguments*)>;
 
   // The APITypeReferenceMap is required to outlive this object.
   // |function_definitions|, |type_definitions| and |event_definitions|
   // may be null if the API does not specify any of that category.
   APIBinding(const std::string& name,
              const base::ListValue* function_definitions,
              const base::ListValue* type_definitions,
              const base::ListValue* event_definitions,
              const base::DictionaryValue* property_definitions,
+             const CreateCustomType& create_custom_type,
              std::unique_ptr<APIBindingHooks> binding_hooks,
              APITypeReferenceMap* type_refs,
              APIRequestHandler* request_handler,
              APIEventHandler* event_handler);
   ~APIBinding();
 
   // Returns a new v8::Object for the API this APIBinding represents.
   v8::Local<v8::Object> CreateInstance(
       v8::Local<v8::Context> context,
       v8::Isolate* isolate,
       const AvailabilityCallback& is_available);
 
   // Returns the JS interface to use when registering hooks with legacy custom
   // bindings.
   v8::Local<v8::Object> GetJSHookInterface(v8::Local<v8::Context> context);
 
  private:
   // Initializes the object_template_ for this API. Called lazily when the
   // first instance is created.
   void InitializeTemplate(v8::Isolate* isolate);
 
+  // Decorates |object_template| with the properties specified by |properties|.
+  void DecorateTemplateWithProperties(
+      v8::Isolate* isolate,
+      v8::Local<v8::ObjectTemplate> object_template,
+      const base::DictionaryValue& properties);
+
   // Handler for getting the v8::Object associated with an event on the API.
   static void GetEventObject(v8::Local<v8::Name>,
                              const v8::PropertyCallbackInfo<v8::Value>& info);
 
+  // Handler for getting the v8::Object associated with a custom property on the
+  // API.
+  static void GetCustomPropertyObject(
+      v8::Local<v8::Name> property,
+      const v8::PropertyCallbackInfo<v8::Value>& info);
+
   // Handles a call an API method with the given |name| and matches the
   // arguments against |signature|.
   void HandleCall(const std::string& name,
                   const APISignature* signature,
                   gin::Arguments* args);
 
   // The root name of the API, e.g. "tabs" for chrome.tabs.
   std::string api_name_;
 
   // A map from method name to method data.
   struct MethodData;
   std::map<std::string, std::unique_ptr<MethodData>> methods_;
 
   // The events associated with this API.
   struct EventData;
   std::vector<std::unique_ptr<EventData>> events_;
 
+  // The custom properties on the API; these are rare.
+  struct CustomPropertyData;
+  std::vector<std::unique_ptr<CustomPropertyData>> custom_properties_;
+
   // The pair for enum entry is <original, js-ified>. JS enum entries use
   // SCREAMING_STYLE (whereas our API enums are just inconsistent).
   using EnumEntry = std::pair<std::string, std::string>;
   // A map of <name, values> for the enums on this API.
   std::map<std::string, std::vector<EnumEntry>> enums_;
 
   // The associated properties of the API, if any.
   const base::DictionaryValue* property_definitions_;
 
+  // The callback for constructing a custom type.
+  CreateCustomType create_custom_type_;
+
   // The registered hooks for this API.
   std::unique_ptr<APIBindingHooks> binding_hooks_;
 
   // The reference map for all known types; required to outlive this object.
   const APITypeReferenceMap* type_refs_;
 
   // The associated request handler, shared between this and other bindings.
   // Required to outlive this object.
   APIRequestHandler* request_handler_;
 
   // The template for this API. Note: some methods may only be available in
   // certain contexts, but this template contains all methods. Those that are
   // unavailable are removed after object instantiation.
   v8::Eternal<v8::ObjectTemplate> object_template_;
 
   base::WeakPtrFactory<APIBinding> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(APIBinding);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_RENDERER_API_BINDING_H_